1. Salling Clicker. Bluetooth remote control for your Mac. Controls (almost) anything and everything, but particularly good for iTunes. Still waiting for a fully-compatible S60 3rd Edition version (the new signing & certification process seems to be causing some problems), but there is a Java version available for download now... which isn't great but you get the idea. There's also a Windows version, but I've not tried it.

2. Lumisoft London A-Z. OK, so not GPS compatible, but if you just want a searchable London streetmap on your phone, this does the job. I like it.

3. Google Maps (sorry, not sure of the link). Google Earth, but, like, on your N80!!! Astounding... but... it gobbles data like chocolate so if you're paying by the megabyte this is probably best avoided (but it works great over WLAN).